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Mutagenesis of retroviral vectors transducing human beta‐globin gene and beta‐globin locus control region derivatives results in stable transmission of an active transcriptional structure.
Author(s) -
Leboulch P.,
Huang G.M.,
Humphries R.K.,
Oh Y.H.,
Eaves C.J.,
Tuan D.Y.,
London I.M.
Publication year - 1994
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1994.tb06605.x
Subject(s) - biology , locus control region , globin , beta (programming language) , gene , microbiology and biotechnology , locus (genetics) , genetics , mutagenesis , promoter , mutation , gene expression , programming language , computer science
Retrovirus‐mediated gene transfer of the human beta‐globin gene into hematopoietic stem cells is an attractive approach to the therapy of human beta‐globin gene disorders. However, expression of the transduced beta‐globin gene linked to its proximal cis‐acting sequences (‐0.8 to +0.3 kb from the cap site) is considerably below the level required for a significant therapeutic effect. The discovery of the beta‐locus control region (beta‐LCR), organized in four major DNase I hypersensitive sites far upstream of the human beta‐like globin gene cluster, provided a potential means to achieve a high level of expression of a linked human beta‐globin gene, but initial attempts to incorporate beta‐LCR derivatives in retroviral vectors resulted in the production of low‐titer viruses with multiple rearrangements of the transmitted proviral structures. We now describe how extensive mutagenesis of the transduced beta‐globin gene, eliminating a 372 bp intronic segment and multiple reverse polyadenylation and splicing signals, increases viral titer significantly and restores stability of proviral transmission upon infection of cell lines and bone marrow‐repopulating cells. These optimized vectors have enabled us to analyze the expression properties of various retrovirally transduced beta‐LCR derivatives in dimethylsulfoxide‐induced murine erythroleukemia cells and to achieve ratios of human beta‐globin/murine beta maj‐globin mRNA, on a per gene basis, as high as 80%.